The results of the third phase of independent testing of Donut Lab solid-state batteries conducted by VTT Technical Research Center in Finland have been officially published. This test focused on the “Self-Discharge” behavior of the battery, which is the loss of power during the battery’s idle period. The test results show that the Donut solid-state battery maintains stable voltage performance after being idle for ten days, showing the power retention characteristics of a normal lithium-ion battery, rather than the linear discharge phenomenon of “supercapacitor” that has been questioned by the outside world.
Background of cooperation between Donut Lab and VTT
Donut Lab previously announced it had commissioned VTT to conduct a series of independent tests aimed at validating the performance claims of its solid-state batteries. This project is named “I Donut Believe” and allows the public to review the actual performance of Donut batteries through test data from a third-party impartial organization. Previously released test projects include “Fast charging performance test“and”High temperature performance test“, and this “self-discharge test” is the third part of the series. It mainly confirms that Dount Battery is not a “supercapacitor” as speculated by the outside world. Although supercapacitors have the characteristics of ultra-fast charging and discharging, they will not be used as batteries for electric vehicles due to their low energy density and poor power retention.
Test methods and conditions
The test was carried out by the internationally renowned VTT Technical Research Center in Finland. During testing, the researchers connected the Donut solid-state battery to a battery tester and monitored it for ten days. Voltage measurements were recorded every 10 seconds to ensure data accuracy. During the test, the battery did not undergo any charging and discharging operations, and the voltage changes in its natural idle state were purely observed.
Test results key findings
According to the test report released by VTT, the following are the core findings of this self-discharge test:
- Voltage stabilization time:The battery voltage stabilized within the first 10 hours of testing and then remained stable without significant drops for the remaining nine and a half days.
- Discharge behavior:The test results confirm that the Donut solid-state battery exhibits “the charge retention characteristics of a normal lithium-ion battery type” rather than the “supercapacitor linear discharge” behavior that some people have questioned. This means that the battery can provide predictable energy storage performance in practical vehicle applications.
- Test environment:Testing is conducted in a controlled laboratory environment with cells at normal room temperature conditions.
The reason why the self-discharge test is critical is that it directly responds to the doubts about Donut’s solid-state batteries. Some people have suspected that Donut’s technology may be closer to a supercapacitor (supercapacitor) than a traditional lithium-ion battery, because of its extremely impressive performance data. VTT’s independent test results show that the battery can maintain a stable voltage after being idle for a long time, complying with the physical characteristics of general batteries and the basic requirements for real-world electric vehicle applications.
However, it should be noted that this test only covers the aspect of “power retention”. Key indicators such as battery cycle life, actual energy density, and mass production consistency still need to be released in subsequent tests. The content of this video is quite short, only about two and a half minutes. Interested friends can watch the video directly:
Preview of next test
According to the official website of “I Donut Believe”, more VTT independent test results will continue to be announced in the future. Friends who want to know more about the detailed data of this self-discharge test can also check it out on the official website.
Source: VTT Technical Research Centre – Self-Discharge Test Report (VTT-CR-00125-26)
Source: KOCPC Chinese